1. Technical Field
The present invention relates to a printing medium separation apparatus, a printing medium separation program, a storage medium storing therein the program, a printing medium separation method, a printing device, a printing device control program, a storage medium storing therein the program, and a printing device control method, all of which are suitable for use of separating an image-printed printing medium into a group of reusable or a group of not reusable.
2. Related Art
When a printing paper is printed with an image on one surface side with the other side left unprinted and the printed paper becomes redundant, the paper is often reused as a scratch paper or again as a printing paper as is blank on the other surface side.
There are various types of technology of automatically identifying whether a paper is a plain blank paper or a paper one surface side of which is printed but the other surface side remains blank (hereinafter, such a paper is referred to as one-side-blank paper), e.g., Patent Document 1 (JP-A-2001-226031) describes a document separation apparatus, and Patent Document 2 (JP-A-10-293503) describes an image forming apparatus.
The document separation apparatus of Patent Document 1 is configured to include: a document transfer unit that transfers a document; an image reading unit that takes charge of image reading from the document in transfer; an image forming unit that outputs a visible image on a predetermined recording medium; a sorting/ejection unit that sorts and ejects the recording medium after image output; a document identification unit that identifies the document by type being the object for image reading; and a separation/ejection unit that separates, based on the identified type of the document, the document after image reading into types, and ejects the document to the sorting/ejection unit. With such a configuration, the document separation apparatus identifies what paper type a document is, whether the document is printed with images on one or both surface sides, and others, and separates and ejects the document based on the identified type.
The image forming apparatus of Patent Document 2 is configured to include: a unit of generating a signal indicating whether a paper loaded to an automatic document feeder (ADF) is a document or a recording paper; a transfer unit that can transfer an ADF-provided recording paper to a feeding unit; and a unit of recognizing, using the signal coming from the signal generation unit, whether the ADF-provided recording paper is blank on the surface based on image information provided by a sensor for the recording paper, and when the recording paper has the blank surface, transferring the recording paper having reached the transfer unit by the transfer by the ADF as such to a paper-feeding unit. With such a configuration, when the recording paper is blank at least on one surface or the other, the recording paper is supplied by the paper-feeding unit for image formation on the blank surface thereof.
The issue here is that, although Patent Document 1 indeed describes the manner of classifying papers into those printed with images only on one surface side, i.e., one-side-blank papers, and those printed with images on both sides or with no image on either surface side, i.e., both-side-blank papers or both-side-printed papers, there is no description at all of identifying how much blank space is left in the both-side-printed paper, and of separating the paper in accordance with the amount of the blank space.
Another issue is that, although Patent Document 2 indeed describes the manner of identifying whether the paper surface is blank or not, and forming (printing) an image on the surface identified as being blank, there is no description at all of identifying how much blank space is left in the image-formed paper, and of forming another image on the blank space when the blank amount is of a predetermined value or larger, for example.
That is, even if a paper is printed with images on both surface sides, depending on the size of the blank space, the paper may be cut and reused as a scratch paper, or be printed again with images on the blank space. However, the technologies of Patent Documents 1 and 2 only identify a paper one surface side of which is perfectly plain blank, and any paper still available for use with some blank space, e.g., half of the paper is blank, is not regarded as being available for recycling use. As such, in view of recycling use, the manner of paper separation of the technologies is not serving well enough.